How to Identify Jerdon's Pit Viper (Identification Guide)
A venomous pit viper of South and Southeast Asia, identified by its brown or olive body with dark blotches, triangular head, and heat-sensing pits.
Read the full Jerdon's Pit Viper encyclopedia entry →
Key identifying features
Jerdon's Pit Viper (Trimeresurus jerdonii) is a venomous pit viper found across parts of South and Southeast Asia, including the Himalayan foothills and adjacent regions. It is identified by a broad, triangular head distinct from the neck, heat-sensing pits between the eyes and nostrils, and a body pattern of dark blotches or crossbands over a green, olive, or brownish background.
Coloration & pattern
The dorsal coloration varies geographically but commonly appears olive-green, yellowish-green, or brownish, marked with a series of darker green, brown, or blackish blotches or crossbands along the back. Some populations show more reddish or rust-toned markings. The belly is typically pale green, yellow, or cream. This blotched or banded pattern, combined with variable base color, distinguishes it from more uniformly green pit vipers.
Head, eyes & scales
The head is broad, triangular, and clearly wider than the neck, typical of pit vipers. Heat-sensing pits are present between the eye and nostril on each side of the face. Eyes have vertically elliptical pupils. Scales are keeled, giving the body a rough texture that aids camouflage among leaf litter and low vegetation.
Size & body shape
Adults typically reach 60 to 90 cm (24 to 35 inches) in length. The body is moderately stout to slender depending on the population, with a prehensile tail adapted for climbing low vegetation and shrubs.
Range & habitat where you'll see it
This species is found in forested hill and mountain regions across parts of the eastern Himalayas, northeastern India, Myanmar, and southern China, generally at moderate elevations. It is found in forest floor leaf litter as well as low shrubs and vegetation, and is active mainly at night.
How to tell it apart from look-alikes
Jerdon's Pit Viper's blotched or banded pattern over an olive, green, or brownish base helps distinguish it from more solidly green species such as the Sri Lankan Green Pit Viper or Large-Eyed Pit Viper. Its triangular head, heat-sensing pits, and vertically elliptical pupils separate it from non-venomous colubrids with similar coloring but round pupils and smooth scales. Because coloration varies significantly across its range, geographic locality combined with the blotched pattern is important for confirming identification.
Frequently asked questions
What pattern distinguishes Jerdon's Pit Viper from other green pit vipers?
It typically shows dark blotches or crossbands over an olive, green, or brownish base, rather than a uniform green body.
Where is Jerdon's Pit Viper found?
In forested hill and mountain regions of the eastern Himalayas, northeastern India, Myanmar, and southern China.
How can it be identified as a pit viper?
By its broad triangular head, heat-sensing pits between eye and nostril, vertically elliptical pupils, and keeled scales.
How large does it grow?
Adults typically reach 60 to 90 cm (24 to 35 inches) in length.
Does its coloration vary across its range?
Yes, coloration and blotch tone vary geographically, so locality is a useful clue alongside the blotched pattern for identification.